1. Field of the Invention
This invention relates generally to pliers that have jaws adjustable to a plurality of preselected positions and, more particularly, to an apparatus for maintaining the two halves of the pliers in a preselected desired position to facilitate altering the jaws from one preselected position to another.
2. Description of the Related Art
Various tool manufacturers produce pliers having jaws that are adjustable to a plurality of preselected positions, such as, the Channel Lock Corporation, which manufacturers adjustable pliers under the trade name CHANNEL LOCK. The jaws of these pliers are adjustable to a plurality of preselected positions via a series of parallel arcuate grooves cut into the interior surface of one of the plier halves. A matching arcuate raised portion on the interior surface of the opposite half of the pliers mates with any selected one of the arcuate grooves to provide a series of positions that correspond to a preselected series of jaw dimensions. The arcuate raised portion, of course, slideably engages the arcuate grooves so as to position the plier halves at a preselected position corresponding to a preselected position of the jaws.
However, in order to engage the arcuate raised portion with one of the parallel arcuate grooves, the pliers are typically manipulated to a fully open position, where the arcuate raised portion disengages from the arcuate grooves, thereby allowing the plier halves to slide relative to one another. The raised arcuate portion moves in a direction generally perpendicular to the arcuate grooves. This movement, however, has a tendency to cause the arcuate raised portion to engage the end portions of the arcuate grooves so as to make sliding adjustment of the plier halves difficult.
Additionally, once the adjustable pliers are manipulated to a preselected position, it is likely that the user will desire that the adjustable pliers remain in this position for an extended period of time. However, quite often the user will pick up the adjustable pliers by a single handle, thereby causing the plier halves to pivot to their fully open, adjusting position and allowing the plier halves to slide from the preselected desired position. It is preferable that the plier halves be restricted from inadvertently moving to the fully open, adjusting position unless specifically desired by the user.
The present invention is directed to overcoming one or more of the problems as set forth above.